A multiple zone HVAC system may be included in a vehicle to provide heating, ventilating and air conditioning to at least one zone within or about a cabin or cargo hold of the vehicle. Heating, ventilating and air conditioning may include other processes, such as dehumidifying, i.e., maintaining a constant temperature while removing moisture, air filtering, or other processes for affecting a climate or environment of the vehicle.
The cost of energy to operate a multiple zone HVAC system may be defined as a parameter of vehicle efficiency. More specifically, for any given road trip, a vehicle may have a maximum attainable fuel efficiency which may be compromised by energy costs associated with operation of the multiple zone HVAC system. Exemplary embodiments may leverage the use of low cost energy, such as free energy or surplus energy, when available, to advantageously operate the HVAC system, and further, may also inhibit the consumption of energy by the HVAC system when the cost of such energy is high.
According to an embodiment of the invention, a vehicle includes a power source including a drivetrain arranged to receive energy from and provide energy to the power source, a heating, ventilating and air conditioning (HVAC) system arranged to receive energy from the power source, a plurality of zones arranged to controllably receive at least one of heating, ventilating and air conditioning from the HVAC system, the plurality of zones including a primary zone and at least one secondary zone and, a controller operable to determine when the HVAC system is providing at least one of heating, ventilating and air conditioning to the primary zone and to determine when the drivetrain is providing energy to the power source or the power source is providing surplus energy to the drivetrain, and in response, to activate a low cost energy mode wherein the HVAC system is operated to provide the at least one of heating, ventilating and air conditioning to the at least one secondary zone.
According to another embodiment, a method of operating a heating, ventilating and air conditioning (HVAC) system in a vehicle having a plurality of zones arranged to receive heating, ventilating and air conditioning from the HVAC system, including a primary zone and at least one secondary zone, the vehicle having a power source arranged to provide energy to the HVAC system and a drivetrain arranged to receive energy from and provide energy to the power source includes the steps of determining if the HVAC system is providing at least one of heating ventilating and air conditioning to the primary zone and determining at least one of the following conditions, the drivetrain is providing energy to the power source or the power source is providing surplus energy to the drivetrain and in response, activating a low cost energy mode wherein the HVAC system is operated to provide the at least one of heating, ventilating and air conditioning to the at least one secondary zone.